Chemistry of Succinimido Esters. IX.

Abstract

Soybean lipoxygenase j (LG I : pH optimum of 9.0) was readily N-arylcarbonylated by N-succinimidyl benzoates (1) and considerably stable up to a high modification ratio. The rate of self-catalyzed destruction of the modified enzyme was less than that of the native one in a borate buffer (pH 9.0). The modification caused expression of the enzyme activity for bringing about oxidation of linoleic acid in hexane-buffer (pH 6.8) biphasic system. The native enzyme showed no activity due to its instability under the experimental conditions. Activity and stability increased with the modification ratio. When bovine serum albumin (BSA) modified by (1) was added to this system, nonnmodified LG showed the activity for causing oxidation. From the above results, it is concluded that imparting hydrophobicity to LG I itself and/or the reaction system is an important factor for expression of enzyme activity in a biphasic system .